Guide
Repair methods a company may propose
Repair proposals are written in trade shorthand: so many piers of such a type, at these marks on a sketch. The tables below translate that shorthand. They take no side between methods, because soil and structure decide which one fits, and those differ from one lot to the next.
Piers: carrying the house down to firmer ground
| Method | How it works | Used for | Worth asking |
|---|---|---|---|
| Steel push piers | Short lengths of steel tube go down one after another next to the footing. A ram does the pressing and the building's own weight is the anchor it works against. Driving stops when the tube will go no further, and a steel bracket then joins pier and footing. | A footing that has dropped beneath a block wall or other heavy load | What depth is the price based on, and what does extra depth add? |
| Helical piers | Think of a very large screw. Steel blades welded near the tip of a shaft bite into the soil as a motor rotates it. The crew watches the resistance on a gauge, since that reading is how the pier's capacity is judged. | Porch columns, single-story walls and other lighter loads; also sand too loose for a pressed pier to seat in | Which torque reading counts as done, and do I receive the log pier by pier? |
| Drilled concrete piers | An auger bores a shaft, a cage of reinforcing bar is lowered in and the shaft is filled with concrete. | Repairs laid out by an engineer who has asked for this type | Whose design is it, and what stops wet sand caving into the bore? |
Lifting slabs and tightening loose soil
| Method | How it works | Used for | Worth asking |
|---|---|---|---|
| Polyurethane foam injection | Two liquids meet at a nozzle pushed through a coin-sized hole in the concrete. The mix swells into rigid foam, packs the hollow and nudges the slab upward. | Interior floors, stoops, drives and pool surrounds that have sunk | How do you stop at the right height, and who pays if the concrete breaks? |
| Cement grout lifting | The older way to do the same thing, known as slabjacking or mudjacking: a sandy cement mix is pumped in through wider holes. | Much the same work as foam, with a heavier material that takes longer to harden | Is the extra weight a concern on the soil under my slab? |
| Compaction grouting | Pipes are driven far below the house into the loose layer. Thick grout forced down them swells into lumps that shove the surrounding sand closer together. | Deep loose ground, sinkhole-affected ground included, normally to a geotechnical engineer's layout | Who drew the layout, and what test proves the ground is firmer afterward? |
Framed floors and walls
Under a house on piers the repair is carpentry and masonry: new or rebuilt piers, adjustable steel posts, added beams and joists. The crawl space page goes through them.
Wall anchors and steel braces hold back basement and retaining walls that are bowing under the pressure of soil. They only come up if your house has a wall with earth against one side.
Three things to settle before you sign
Hold or lift?
Every method can hold a foundation where it is. Some can also raise it. Lifting recovers lost height and closes gaps, and it can crack finishes or pipes on the way. Ask what the proposal promises: no further movement, a lift to a stated level, or both.
What about the cause?
No method repairs the reason the soil moved. If a leaking pipe, roof runoff or a tree is part of it, that needs dealing with as well, often by another trade.
Who designed it?
Ask whether a Florida engineer has reviewed the plan for your house, or whether it is the company's standard layout.
Questions about methods
Which method suits sandy soil?
There is no single answer. In loose sand the question is how deep the firm layer is, and whether the loose zone should be bridged with piers or tightened with grout. Reasonable companies can differ. If two proposals disagree, an independent structural or geotechnical engineer can referee.
How long does a repair take?
It varies with the method and the number of locations. Ask the company for its schedule in writing, including the permit and the final inspection by the building department.
Ready to have the house looked at?
Only someone standing at the house can tell you what is going on under it. Call, explain what you have noticed, and ask for an inspection.
Describe the problem, book an inspection
Say where the cracks or dips are and when you first saw them. The independent local foundation repair company you reach can set a time to look at the house.
Call (407) 598-8829The call may be recorded. See how referrals are paid for and what happens to your details.